Water Service Pipes

Overview

Engineering reference data for Water Service Pipes in fluid mechanics.

Key Formulas

Reynolds Number

$Re = \frac{\rho v D}{\mu}$

Ratio of inertial to viscous forces — determines flow regime.

Bernoulli's Equation

$P + \frac{1}{2}\rho v^2 + \rho g h = \text{const}$

Conservation of energy for steady, inviscid, incompressible flow.

Continuity Equation

$A_1 v_1 = A_2 v_2$

Conservation of mass for incompressible flow.

Darcy-Weisbach

$\Delta P = f \frac{L}{D} \frac{\rho v^2}{2}$

Pressure drop due to friction in a pipe.

Variables

Symbol	Description	Unit
$Re$	Reynolds number	—
$\rho$	Fluid density	kg/m³
$v$	Flow velocity	m/s
$D$	Characteristic dimension	m
$\mu$	Dynamic viscosity	Pa·s
$P$	Pressure	Pa
$f$	Darcy friction factor	—

Piping Materials & U.S. Standards

Materials in Water Service Pipes

Commonly Used Materials:

• Cast iron pipe (ductile pipe) - used in large water mains.
• PE - Polyethylene.
• PVC - Polyvinyl Chloride.
• PB - Polybutylene.
• Asbestos cement pipe.

Other Approved & Less Common Materials:

• ABS - Acrylonitrile Butadiene Styrene.
• Brass pipe.
• Copper tube - can be used as service lines without joints. Primarily used as water distribution pipes.
• CPVC - Chlorinated Polyvinyl Chloride.
• Galvanized Steel.

Key Properties

A water service line extends from the potable water source to the building interior, where it becomes a water-distribution pipe. Key properties for material selection include:

• Pressure Rating: Must withstand pressure from the water source, pumps, or static head. A common rating is >160 psi (11 bar).
• Temperature: Typically designed for temperatures below ~75°F (25°C).

References

• Original Source